KotŌ, Bunjiro

(b. Tsuwano, Iwami [now Shimane prefecture], Japan, 4 March 1856; d. Tokyo, Japan, 8 March 1935)

geology, seismology.

Born into a feudal samurai clan from Tsuwano, Kotā was the eldest son of Jisei Kotō. He went as a recommended student to Tokyo to study Western science. In 1879 he graduated from Tokyo Imperial University, where he was the first student to specialize in geology.

In 1881 Kotō entered the University of Leipzig, where he studied geology under Credner and petrogra. phy under Zirkel, a pioneer of microscopic petrology. Kotō entered the University of Munich in 1882 but received his Ph.D. from Leipzig in 1884. He became professor at Tokyo University in 1885 and directed teaching and research in the department of geology together with Tsunashiro Wada and Toyokichi Harada. He held this professorship until 1921.

In the early stage of his research Kotō studied mainly metamorphic rocks of Japan, and his papers introduced uniquely Japanese varieties of rock to geologists throughout the world. In these works Kotō proposed the terms Sambagawa system, Mikabu system, Takanuki system, and Gozaisho system.

In 1892, following the great Nōbi earthquake (28 October 1891) in which 7,000 persons were killed, an investigatory committee was formed by the ministry of education. Kotō was an active member and directed research on volcanoes. About this time his interest turned from the petrology of metamorphic rocks to volcanoes, earthquakes, and geotectonics. The photograph of the Neo-dani Fault, taken and published by Kotō in his paper on the Nōbi earth. quake, was reprinted in many geology textbooks. Between 1893 and 1931 Kotō published many articles on earthquakes, volcanoes, morphology, and geotec. tonics. In “The Scope of the Volcanological Survey of Japan” (p. 93), he wrote:

So-called tectonic fracture lines play a most important part. It is the key with which the structure and the origin of continents and oceans, mountains and lands, tablelands and basins, etc., arc disclosed and explained. I must say plainly, that the chains of volcanoes, the system of mountains, and the nonvolcanic earthquake appear to me to have very intimate and fundamental relation with the so-called tectonic lines.

During the first years of the twentieth century Kotō published many papers on the geology and topography of the Korean peninsula. His works on the geotectonics of the Japanese islands of the Pacific Ocean date from about 1930.

Kotō had considerable administrative authority at Tokyo; and although at times apt to be dictatorial, he was professionally respected. Not until 1921 did he allow a lectureship of applied geology (in ore deposit) to be established.

The petrology of Kotō was descriptive. His geotec. tonic theory was essentially static and was based on the concept of the fracture-line. Late in his life geological research underwent a kind of revolution: experimental petrology was developed, and comparative tectonics, treating the movement of the earth’s crust, appeared.

BIBLIOGRAPHY

I. Original Works. Among Kotō more important papers arc “Studies on Some Japanese Rocks,” in Quar. terly Journal of the Geological Society of London, no. 159 (1884), 431; “A Note on Glaucophane,” in Journal of the College of Science, Imperial University of Tokyo, 1 (1887), 85; “Some Occurrence of Piedmontite in Japan,” ibid., 303; “On the So-Called Crystalline Schist of Chichibu,” ibid, 2 (1888), 77; “On the Cause of the Great Earthquake in Central Japan 1891,” ibid., 5 (1893), 293; “The Archaean Formation of the Abukuma Plateau,” ibid., 197; “The Scope of the Volcanological Survey of Japan,” Earthquake Investigation Committee, no. 3 (1900). p. 89; “Topography of the Southern Part of Korea,” in Geological Magazine of Japan, 13 , no. 150 (1901), 342, and no. 151 (1901), 413;“Topography of the Northern Part of Korea,” ibid., 14 , no. 162 (1902), 399. and no. 163 (1902). 467; “An Oro. graphic Sketch of Korea,” in Journal of the College of Science, Imperial University of Tokyo, 19 (1903), 1; “The Great Eruption of Sakurajima in 1914.” ibid., 38 , art. 3 (1916), 3; “On the Volcanoes of Japan,” in Journal of the Geological Society of Japan, 23 (1916), 1, 17, 29, 77, 95;“The Rocky Mountain Arcs in Eastern Asia.” in Journal of the Faculty of Science, Tokyo University, 3 , pt. 3 (1931), 131; and “The Seven Islands of lzu Province: A Volcanic Chain,” ibid., pt. 5 (1931).

II. Secondary Literature. There is a biography of Kotō in Japanese by Matajiro Yokoyama in Journal of the Geological Society of Japan, 42 (Apr. 1935), 39. A brief English biography with complete bibliography and portrait is T. A. Jaggar, “Memorial of Bunjiro Koto.” in Pro. ceedings. Geological Society of America (1936), pp. 263-272.

Hideo Kobayashi